Mail rule script stopping after one message?

I have a script for moving some SENT messages to a specific folder. It executes via a rule that triggers whenever any message is received. Sometimes, only one message is moved at a time and I do not know why. The script should move all relevant messages in the 'repeat' loop.

Script:

using terms fromapplication "Mail"

on perform mail action with messagestheSelectedMessagesfor ruletheRule

setmessageListto {}

setxtomessagesinmailbox "Sent Messages" inaccount "xxx"

set messageList to x

setxtomessagesinmailbox "Sent Messages" inaccount "yyy"

set messageList to messageList & x

setxtomessagesinmailbox "Sent Messages" inaccount "zzz"

set messageList to messageList & x

repeatwithifrom 1 tocountitemsinmessageList

set msg to item i of messageList

if all headers of msg contains "VC:" or all headers of msg contains "HOA:" then

set mailbox of msg to mailbox "VC-HOA" of mailbox "Local"

end if

endrepeat

end perform mail action with messages

endusing terms from

Thanks.